The present invention relates to peeling peelable products, such as potatoes.
It is previously known to utilize cutting means, such as knives in peeling devices to peel a product. However, these known knife peelers have the drawback that they are unsuitable for peeling a product in a single step. This is because knives are sensitive to sand and other impurities that may be present when potatoes, for example, are peeled. When a product is peeled in one step using such a knife peeler, the knives become blunt quite rapidly and thus have to be replaced.
To avoid constant replacement of knives in a knife peeler, it is known to carry out the peeling with two different peeling devices of which the latter is a knife peeler. In this case the first peeling device is a peeling element having a rough scraping surface. The rough scraping surface of the peeling element provides the first peeling step. In the first peeling step, impurities, such as sand, are removed. After the first peeling step, the product is conveyed to a second peeling device, which is a knife peeler. The knife peeler thus finishes the peeling of the product without its knives coming into contact with sand or the like impurities. The drawback in this known solution is, however, that the peeling of a product requires two different peeling devices, which increases the costs of the peeling apparatus and, moreover, the peeling apparatus requires a relatively large space.
The object of the present invention is to solve the above problems. This is achieved with a peeling element having an elongated or rod-like shape and being attached to means for rotating the peeling element around a rotation axis and comprising peeling means on an outer surface. The peeling element of the present invention is characterized in that on a first part of said peeling element said outer surface comprises a rough scraping surface, and that on a second part of said peeling element said outer surface comprises at least one cutting means.
The object of the present invention is also achieved with a peeling device comprising: at least a pair of adjacent peeling elements having a rod-like shape and being attached to means for rotating the peeling elements around rotation axes, the outer surfaces of the peeling elements comprising peeling means. The peeling device of the invention is characterized in that on a first part of the peeling elements the outer surface of the peeling elements comprises a rough scraping surface, and that on a second part of the peeling elements the outer surface of the peeling elements comprises at least one cutting means.
The invention is based on the idea of utilizing a peeling element capable of peeling with both a rough scraping surface and a cutting means. Such a peeling element allows a product to be peeled in the same peeling device in such a way that the rough scraping surface of the peeling element starts the peeling and the cutting means of the peeling element finishes the peeling. When peeling is started with the rough scraping surface, the cutting means does not come into contact with sand or the like impurities. The most important advantages of the peeling element and the peeling device of the invention include a reduction in the costs of the peeling apparatus and the space required by it, since they allow a product to be peeled in a single peeling device.
The peeling element of the present invention may be composed of a single part with a combination of a carborundum surface and knives. An alternative is a two-piece peeling element composed of a first part comprising a carborundum surface and a second part comprising knives. In this case the two parts are coupled together, both parts being for example hollow, allowing them to be threaded on a common shaft for making them rotate together.
In a preferred embodiment, the peeling device comprises a worm conveyor for moving the product to be peeled from the rough scraping surface of the peeling element towards its knives. This allows the peeling device to be made entirely automatic, i.e. it is capable of receiving a peelable product from an inlet, peeling the product and moving the ready-peeled product to an outlet.